Top-Level Engine Mariner Subject Matter Expert - The candidate must hold or have held, at a minimum, a U.S. Coast Guard-issued Merchant Mariner Credential (MMC) endorsed as Chief Engineer of vessels of any horsepower (Unlimited Horsepower) for Motor (Diesel), Steam, or Gas Turbine propulsion or a U.S. Coast Guard-issued Merchant Mariner Credential (MMC) endorsed as First Assistant Engineer of vessels of any horsepower (Unlimited Horsepower) for Motor (Diesel), Steam, or Gas Turbine propulsion, and a minimum of five (5) years of experience sailing on that credential. Required Credentials: Must hold or have held, at a minimum, a valid U.S. Coast Guard-issued MMC endorsed as Chief Engineer of vessels of any horsepower (Unlimited Horsepower) for Motor (Diesel), Steam, or Gas Turbine propulsion OR a U.S. Coast Guard-issued MMC endorsed as First Assistant Engineer of vessels of any horsepower (Unlimited Horsepower) for Motor (Diesel), Steam, or Gas Turbine propulsion.